The Academy of Sciences of the Czech rebublic - ASCR

IPP begins production of magnetic field sensors for the ITER project

IPP launched the production of worldwide unique OVSS steady magnetic field sensors. The sensors  will be installed on the ITER thermonuclear reactor in France. OVSS have been developed in the UFP in the wide international co-operation with other scientific institutions and industrial enterprises.


OVSS (Outer Vessel Steady-state Sensors) are designed to measure steady-state magnetic field under extreme conditions of thermonuclear reactors. In the near future, they will be installed on the ITER thermonuclear reactor being constructed in France, which will be the world's largest nuclear fusion research facility. Sensors were developed at IPP in Prague in extensive international cooperation with ITER International Fusion Energy Organization (France), Institute of Physics of the CAS, Institute of Nuclear Physics of the CAS, Research Center Řež, Petr Sládek, HVM Plasma Ltd., Plasma Technologic Ltd., PragoBoard Ltd., AVS Added Value Industrial Engineering Solutions SL. (Spain) and LT Calcoli Srl. (Italy). The whole production process will be managed and coordinated by IPP .

Strategie AV21 Developed Hall sensor detail

Photo: Slavomír Entler, IPP.
The Hall sensors will be installed in the ITER reactor in three sectors of the vacuum chamber. In each sector, 20 sensor units will be deployed, containing a pair of sensors positioned perpendicular to each other to measure the tangential and normal component of the magnetic field. The sensor operating temperature will be 90-100 °C, while the sensor temperature can reach up to 220 °C during the vacuum vessel baking. Total neutron fluence over the lifetime of the sensor reaches approximately 1.3x10 22 n/m 2.


Strategie AV21 Miniature Bismuth Hall Sensors for the ITER Thermonuclear Reactor

Photo: Slavomír Entler, IPP.
Developed Hall sensors are 6.4 mm x 6.4 mm in size and consist of a 0.63 mm thin ceramic plate. On the ceramic plate, a copper layer of 127 μm is applied using Direct Bonded Copper technology. The bismuth detection layer is deposited by magnetron sputtering and has a thickness of 1 μm. The sensors will be placed in pairs in the stainless steel sensor units. The sensor assembly also includes a control unit that processes the sensor signal. The measurement error of the sensor assembly is 0.1% in the measuring range of ± 2.5 T.

Strategie AV21 Outer vessel steady-state sensor unit















Picture: ITER Organization.

7 Feb 2018